When an Internet protocol (IP) datagram carrying information destined for a target communication device is sent from a packet data service nodes (PDSNs) to a base station controller/packet control function (BSC/PCF) while the packet session is in dormant, the BSC/PCF needs to determine whether the information should be sent as short data bursts (SDBs). One algorithm is to use the size of the received information packet as a filtering criterion. That is, when the received information packet is found to be smaller than a predetermined size, the information packet may be sent to the target mobile station as SDB over the forward common channel, for example, without waiting for the traffic channel to be activated. Otherwise, traffic channel needs to be re-established before sending the information packet. This algorithm may not work well in group call services, for example, where clients and servers send messages varied in size when the data session is in dormant state. However, not all these messages are time critical and, therefore, need not to be sent as SDB. Some large messages may need to be sent as SDB while some small messages may need to be delivered after the traffic channel is re-established. Using a large packet size as a filtering criterion may trigger many small messages to be sent as SDB and, therefore, cause extensive loading on the common channel. On the other hand, if a small packet size is used, larger messages that are time-critical may not be immediately sent as SDB.
There is a need, therefore, for mechanisms to determine what messages need to be communicated in SDB such that no time-sensitive message is delayed.